Heat exchanger



1. THOMPSON.

HEAT EXCHANGER; APPLICATION FILED AUGA, I919.

Patented Apr. 4, 1922.

4 SHEETS-SHEET I.

Z5 6.9 /NLET FOR I1 T O L J. THOMPSON.

I HEAT EXCHANGER. APPLICATION FILED AUG.4, 1919.

1,41 1,3 1 3 Patented Apr. 4, 1922.

4 SHEETS-SHEET21 J. l. THOMPSON.

HEAT EXCHANGER.

APPLICATION FILED AUG-4,1919.

Patented Apr. 4, 1922.

4 SHEETS-SHEET 3- Cow OIL mmsr l. THOMPSON.

HEAT EX'CHANGER. APPLICATION FILED AUG-4| 1919.

Patented Apr. 4, 1922.

4 swans-aunt 4.

UNITED STATES PATENT OFFICE JOHN I. THOMPSON, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE KOPPERS COMPANY, OF PITTSBURGH. PENNSYLVANIA. A CORPORATION OF PENNSYLVANIA.

HEAT EXCHAN GER.

Specification of Letters Patent.

Patented Apr. 4, 1922.

Application filed August 4, 1919. Serial No. 315,110.

To (1.! Z whom it may concern Be it known that I, Jonx I. TuoMrsoN, a citizen of the Ifnitcd States. residing in Pittsburgh, in the county of Allegheny and State of Pennsylvania. have invented a new and useful Improvement in Heat Exchangers, of which the following is a specification.

This invention relates generally to heat exchangers for hot and cold mediums, and has one especially valuable application in the recovery of hydrocarbons from absorbing oils. In order to attain economy in operation, when effecting the recovery of hydrocarbons from wash oils, it is necessary to conserve as much as possible the heat essential for raising the temperature of the wash oils sufficiently to effect distillation of the hydrocarbons. It will be understood, however, that the invention is capable of other valuable applications than the specific use here mentioned and described in the ensuing specification.

Before proceeding to a description of the present invention, a brief outline of the method involved in the recovery of hydrocarbons from wash oils is given in order that a thorough understanding be had of at least one valuable application of the invention.

The gases of distillation from coal or other fuel are first cooled to about 77 F. by passing them through coolers, after which they are passed over washers where they are brought into contact with oils capable of absorbing the hydrocarbon constituents of the gases, notably benzol and its homologues, at a low temperature, and which oils, by subsequent heating to about 226 F. and treating with steam will release the absorbed hydrocarbon constituents. Tar oil, straw oil and mineral oils are commonly the oils employed for this purpose. The hydrocarbons. such-as benzol and its homologues are then recovered and distilled from the absorbing or wash oil, requiring a great amount of heat for raising the temperature of the wash oil sufliciently to effect the distillation of the hydrocarbons.

In plants of large capacity it is, for economical reasons, necessary to conserve as much of this heat required in the distillation as possible and for this purpose heat exchangers have heretofore been employed for transferring heat units from the preheated oil discharged from the still after the absorbed hydrocarbons have been given off to the relatively cool wash oils containing the hydrocarbons.

As is well known, most oils which are used for absorbing hydrocarbons such as benzol and the like have a corrosive effect on metals at high temperature, especially if they contain traces of ammonia absorbed from the gases of distillation of coal and means must be provided therefore to allow the easy and ing or replacements may be made with great facility.

Another highly important object of the invention is the provision of a heat exchanger adapted for continuous flow of the hot and cold mediums within the heat exchanger and concurrently constructed of a number of units each one of which may be removed for cleaning, repair or replacement purposes without in any way disturbing or effecting the operation of the other units.

Still another important object of the invention is the provision of a heat exchanger in which a prolonged and eflicient heat transfer action is maintained continuously, thereby effecting a high degree of conservation of heat.

\Vith the above and other objects in View the invention consists in certain novel arrangements, constructions and combination of parts hereinafter described in a preferred form and particularly pointed out in the claims at the end of the specification.

In the drawings,

Figure 1 is a plan view of a heat exchanger constructed in accordance with the present improvements, with portions of the tank covers broken away to illustrate the interior construction Fig. 2 is a side sectional elevation of the heat exchanger illustrated in Fig. 1;

Fig. 3 is a longitudinal sectional elevation of one of the nests of pipes hereinafter more fully described;

Fig. 4 is a plan view of the nest ofpipes illustrated in Fig. 3;

Fig. 5 is an end elevation of the heat exchanger viewed from the right of Fig. 1;

Fig. 6 is a diagrammatic view illustrating the path of travel of one of the mediums in the nests of pipes.

Fig. 7 is a diagrammatic view illustrating the path of travel of the other medium in the tank in which the nests of pipes are supported;

Fig. 8 is an elevation of a head mounted at one end of each nest of pipes and viewed from the left of Fig. 3.

Fig. 9 is a vertical section taken in a plane indicated by the line 99 of Fig. 3;

Fig. 10 is a vertical section in a plane indicated by the line 10-10 of Fig. 3;

- Fig. 11 is a sectional elevation of the head at the opposite end of each nest of pipes, the view being in a plane indicated by the line 1111 of Fig. 3.

Fig. 12 is a horizontal section in a plane indicated by the line 12-12 of Fig. 3;

Fig. 13 is a horizontal section in a plane indicated by the line 1313 of Fig. 3, and

Fig. 14 is a horizontal section in a plane indicated by the line 1.414 of Fig. 3.

In the illustrated embodiment of the invention, the heat exchanger is especially adapted for the purpose of effecting heat transfers between the relatively cool wash oil passingto a distilling apparatus and the preheated oil discharged from the distilling apparatus, of a by-product recovery plant, and for convenience the present description of the heat exchanger will be confined to this use of the invention. Features of construction of the heat exchanger are readily susceptible of other valuable applications however and it is. manifest that the scope of the invention is by no means'confined to the specific use and specific embodiment herein described.

Referring to the drawings there is shown a platform 21 constructed preferably of masonry and adapted to sustain the tank and other partsvof the exchanger. The platform 21 is positioned within a framework structure composed of four uprights 22 connected adjacent their upper ends by longitudinallyextending horizontal bars 23, andfurther braced by horizontal diagonal bars 24 extending to the four corners of the pair' of longitudinal bars 23. Supported beneath the pair of longitudinal bars 23 is a pair of tracks 25 on which run block and tackles intitions 32 supported upon the bottom 29 of the tank and extending to the opposite end walls 31 of the latter. Communication between the several compartments 33 of the tank is afforded by means of openings 34 in the partition walls 32. Said openings 34 are preferably located near the bottom of the tank-and the openings of adjacent partitions 32 are respectively positioned at opposite ends of the tank as clearly shown in Fig. 1. This requires a flowing medium, for example the hot oil, to travel the entire length of each compartment in the tank before passing to the next compartment. Mounted on the top of the tank and positioned over each compartment thereof is a cover 35, there being a separate cover for each compartment as shown, whereby access may be had to the interior of each one of the compartments without disturbing the other compartments. If desired each cover 35 may be provided with a pair of upstanding ears or lugs 36 adapted to be engaged by the hooks 27 to permit removal of the cover from the top of the tank. Communicating with the interior of the tank and positioned at one end of a side wall 30 and near the top of the tank is an inlet nozzle 37 for the hot oil flowing into the interior of the tank. The outlet nozzle 38, similarly constructed, is positioned near the bottom of the tank at the same end of the opposite side wall 30, as the inlet nozzle 37 said outlet nozzle also communicating with the interior of the tank and constituting the discharge for the oil after it has passed through the several compartments of the the other medium, for example the cold oil flows. The several nests of pipes are preferably each of multiple-pass construction and are adapted to be connected together in series, as will hereinafter appear, whereby embodies a lower series of pipes 40, two intermediate series 41, 42 and an upper series 43, all of said pipes of the several series being rigidly secured at their opposite ends,

in any approved manner, in the end baflie plates 44, 45. Secured to the end battle plate 45 is a head 46 provided with a vertical inlet passage 47 which communicates at its lower end with a chamber 48 the latter communicating with the mouths of the several pipes of the lower series 40, as clearly shown in Figs. 3 and 14. Also formed in the head 46 is a second chamber 49 separated by a horizontal wall 50 from said chamber 48, and communicating with the mouths of the two intermediate series of pipes 41, 42. A third chamber 51 is formed in the head 46, said chamber 51 being separated from chamber 49 by a horizontal wall 52' and communicating with the mouths of the series of pipes 43. Chamber 51 discharges into an outlet passage 53 formed in the head 46. A head 54 is secured to the baffle 44 at the opposite end of the nest of pipes and said head 54 is provided with upper and lower chambers 55, 56 separated from each other by a horizontal wall 57. The upper chamber 55 of the head 54 communicates with the mouth of the series of pipes 42, 43 and the lower chamber 56 communicates with the mouths of the series ofpipes 40, 41. Secured respectively, by means of any approved couplings 58, to the inlet and'dischargepassages 47, 53 of the head 46 are inlet and discharge pipes 59, 60, these inlet and dis charge pipes extending the length of the nest of pipes and adapted at their opposite ends to be connected with the manifold, hereinafter described, by means of suitable detachable pipe coupling members 61.

The cold oil or other medium flows through the inlet pipe 59 of each nest of pipes, thence through the inlet passage 47 of the head 46 to the chamber 48, from which chamber it enters the first series of pipes 40 and flows along the entire length of said pipes 40 into the lower chamber 56 of the other head 54. Fron 1 the chamber 56 of the head 54 oil fiows into the next series of pipes 41 and back along the entire length of this series of pipes into the chamber 49 of the head 46. The oil then flows from the chamber 49 into the next series of pipes 42 and along their entire length into the chamber 55 of the head 54 and from chamber 55 it flows into the top series of pipes 43 back into the upper chamber 51 of the head 46 and finally, through the outlet passage 53, fiows into the discharge pipe 60. From the discharge pipe 60 the oil flows into the inlet pipe of the next nest of pipes of the series, or if the nest be the last nestof the series the oil discharges from the apparatus.

\Vhen positioned in a compartment 33 of the tank, the end baflies 44, 45 of each nest of pipes are adapted to rest on the bottom 29 of the tank; but are located a substantial distance beneath the top 35 of the tank compartment. Substantially midway between their opposite ends, the several pipes constituting the nest of pipes are passed through and supported by an intermediate battle 62, said baflle 62 also being adapted to rest on the bottom of the tank and also dimensioned so that it is spaced a substantial distance from the top of the tank when the nestis in position in the tank. Between the intermediate baflle 62 and both end battles 44 and 45 are bafiies 63, 64 through which are passed the several pipes of the nest and also the inlet and discharge pipes 59, 60, as shown in Figs. 3 and 9. These battles 63, 64 are dimensioned to extend to the top of the tank compartment when in position therein but to be spaced from the bottom of the latter. All of the several battles through which the pipes of the nest are passed and supported extend transversely clear across the tank. as shown in Fig. 1, and the opposite vertical edges of said bafties are adapted to enter groovesof suitable vertical wedges 65 for maintaining a tight fit at the vertical edge of the battles and the proximatelongitudinal walls of each compartment. may be braced by diagonal braces 66 extending between and connected in any preferred manner with adjacent battles as shown in Fig. 2.

Mounted at one end of the tank, see Figs. 1 and 5, is a manifold 67 constructed of suitable piping and having branches 68 extending respectively to the several inlet and discharge pipes 59, 60 to the several nests of pipes in the series, each branch being adapted to be connected with an inlet or discharge pipe 59 or 60 by means of the hereinbet'ore mentioned detachable pipecoupling .61. Preferably the manifold 67 is formed of a nected together by means of apipe union 73 joining the adjacent branches 68 of saidsections. The inlet 74 communicates with the outermost vertical branch 68 of section 69 and an outlet 75 with the outermost vertical branch of the section 70. The branches 68 communicating with the inlets and outlets 74, 75 are respectively fitted with pairs of valves '76 located between the inlets and outlets, and the two branches 68 connected by the pipe union 73 are equipped with similar pairs of valves77. The remaining branches 68 are equipped with valves 78. This valve equipment permits one entire section 69 or '70 of the manifold to be cut off from the flow by manipulation of the proper valves without disturbing the continuity of the flow in If desired, each nest of pipes the other section of the manifold. The valve equipment also permits any one of the branches 68 of the manifold to be cut off from the flow without disturbing the flow in the other branches.

WVith the foregoing construction, each nest of pipes for the circulation of one medium may be removed, together with its baffle plates as a unit, from a compartment of the tank in which it is mounted, independently of the remaining nests of pipes in the other compartments of the tank. This operation may be quickly accomplished by shutting off the flow to and from the nest of pipes it is desired to remove, i. e., by manipulating the valves of the manifold connected with the outlet and discharge pipes 59, 60 of said nest of pipes, and next disconnecting the out- .let and discharge pipes 59, 60 from the manifold by removing the coupling 61. l/Vhen this has been accomplished the entire' nest of pipes and its baffles as a unit may be lifted out from the tank compartment by moving the block and tackles 26 over the nest of pipes and engaging the hooks 27 of the latter with the nest of pipes. In order to facilitate removal of the nest of pipes, the end baffles 44, are provided with upstanding cars 79 having holes adapted to receive the hooks 27 of the block and tackles 26. The nest of pipes may be lifted clear of the tank and moved by the block and tackles along their tracks 25 to a point indicated by dotted lines in Fig. 5 where the entire unit may be lowered for convenient inspect-ion, cleaning or repair. It will be noted that the exteriors of the nest of pipes are readily accessible for cleaning or repair purposes as soon as each nest has been removed from its tank compartment. If it be desired to reach the interior of the pipes the heads 46, 54 may be removed from the ends of the several pipes and the interior of the pipes cleaned or flushed out.

A further feature of advantage in the present heat exchanger lies in the fact that the flow of the. two mediums undergoing heat transfer is accomplished in a manner which insures a highly efficient transfer of heat from one medium to the other. As shown in the diagram of Fig. 6 the one medium, for example the cold oil flows in an elongated path along the inlet 59 and thence back and forth through similar elongated paths through the multiple passes of pipes 40, 41, 42 and 43 to the discharge pipe 60 through which it flows in an elongated path to the manifold and thence to the next adjacent nest of the series. On account of the baffle plate construction however the other medium, for example the hot oil from the distilling apparatus, enters the outermost compartment at one end of the tank and flows in paths transversely with respect to the I elongated paths of flow of the cold oil in the pipe nests, for the entire length of the first or outermost compartment before it passes to the next compartment of the tank. The path of hot oil is indicated by the diagram in Fig. 7 and as shown therein the hot oil enters the tank at the inlet 37. In its flow through the first compartment 33 passes diagonally from the inlet 37 to the bafiie 63, thence to and under baffle 63 thence diagonally upwardly and over baffle 62, thence dia'gonally downwardly and under baffle 64 and finally diagonally upwardly and over baffle 45 to the opening 34 in the partition wall, through which the hot oil flows into the next adjacent compartment of the tank.

It will be noted by inspecting the diagram of Fig. 7 that this diagonal flow or action is maintained in each of the several comp-artments of the tank. As a result of the opera tion of the improved means herein described for positively directing the one medium to flow in paths transverse or diagonal with respect to elongated paths of flow of the other medium, a greatly prolonged heat transfer action is maintained co-extensively with said elongated paths and a highly efficient conservation of heat is attained.

The invention is herein above set forth as embodied in a particular form or construction but may be variously embodied within the scope of the claims hereinafter made.

I claim:

1. In a heat-exchanger for hot and cold mediums, in combination; a tank subdivided into communicating compartments, for the circulation of one medium; baflies transverse of each compartment; and a multiple-pass nest of pipes, for the fluent and refiuent circulation of the other medium, supported within and removable as a unit from each of said compartments; substantially as specified.

2. In a heat-exchanger for hot and cold mediums, in combination: a tank subdivided into communicating compartments, for the circulation of one medium; baffles transverse of each compartment; and a nest of pipes, for the circulation of the other medium, supported within and removable as a unit from each of said compartments in a direction parallel to the planes of said baffles; substantially as specified.

3. In a heat-exchanger for hot and cold mediums, in combination: a tank subdivided into communicating compartments, for the circulation of one medium; baflles transverse of each compartment; and a nest of pipes, for the circulation of the other medium, passing through said battles and with them forming a unit supported within and removable from each of said compartments ina direction parallel to the planes of said baffles; substantially as specified.

4. In a heat-exchanger for hot and cold mediums, in combination: a tank subdivided into communicating compartments, for the circulation of one medium; baflles transverse of each compartment; and a multiple-pass nest of pipes, for the fluent and refluent circulation of the other .medium, passing through said bafiies and with them forming a unit supported within and removable from each of said compartments: substantially as specified.

5. In a heat-exchanger for hot and cold mediums, in combination: a compartment provided with transverse battles, for the circulation of one medium; and a nest of pipes, for the circulation of the other medium, passing through said baflles and with them forming a unit supported within and remov able from said compartment in a direction parallel to the planes of said baffles; substantially as specified.

6. In av heat-exchanger for hot and cold mediums, in combination: a compartment provided with transverse baifles, for the circulation of one medium; and a multiplepass nest ofpipes, for the circulation of the other medium, passing through said baflies and with them forming a unit supported Within and removable from said compartment in a direction parallel to the planes of said battles: substantially as specified.

7. In a heat-exchanger for hot and cold mediums, 1n combination: a baflled compartment, for the circulation of one medium: and a multiple-pass nest of pipes. for the fluent and refluent circulation of the other medlum, supported within and removable as a unit from said compartment: substantially as specified.

8. In a heat-exchanger for hot and cold -mediums, in combination: a baflied compartment, for the circulation of one medium and a nest of pipes, for the circulation of the other medium. supported wholly within and removable as a unit transversely from said compartment; substantially as specified.

9. A heat-exchanger for hot and cold mediums, comprising, in combination, a tank for the circulation of one medium. batfles within said tank, and a nest of pipes. for the .circulation of the other medium, supported by said baifles and with them forming a unit supported wholly within and removable transversely from said tank: substantially as specified.

10. In a heat-exchanger for hot and cold mediums, comprisin in combination. a tank for the circulation of one medium. baflies within said tank. and a multiple-pass nest of pipes. for the circulation of the other medium, supported by said bafi'lles and with them forming a unit supported wholly within and removable thansversely from said tank; substantially as specified.

11. In a heat-exchanger for hot and cold mediums. in combination: a tank subdivided into compartments. for the circulation of one medium; a nest of pipes. for the circulation of the other medium, supported within each of said compartments: a manifold for supplying the circulatin medium to the several nests of pipes; and couplings independently connecting the respective nests of pipes with said manifold. whereby each nest of pipes may be removed as a unit from its compartment independently of the other nests of pipes; substantially as specified.

12. In a heat-exchanger for hot and cold mediums, in combination: a tank subdivided into communicating compartments. for the circulation of one medium; removable battles transverse of each compartment; a nest of pipes, for the circulation of the other medium, passing through said battles and supported within each of said compartments; a manifold for supplying the circulating medium to the several nests of pipes; and couplings independently connecting the respective nests of pipes with said manifold, whereby each nest of pipes with its supporting baflles may be rcmoved as a unit from its compartment independently of the other nests of pipes; substantially as specified.

13. In a heat-exchanger for hot and cold mediums, in combination: a compartment for the circulation of one medium, transverse battles. in said compartment, alternately spaced from the top or bottom of said compartment; and a multiplepass nest of pipes. for the fluent and refluent circulation of the other medium. passing through said baffles; the entire nest of pipes and the baffles being supported within and removable as a unit transversely from said compartment; substantially as specified.

1- In a heat-exchanger for hot and cold mediums, in combination: a tank subdivided into communicating compartments. for the circulation of one medium; transverse baifles. in each compartment, alternately spaced from the top or bottom of said compartment; and a nest of pipes, for the circulation of the other medium, passing through said battles and with them forming a unit wholly supported within and removable transversely from each of said compartments; substantially as specified.

15. A heat-exchanging apparatus for hot and cold mediums, comprising, bafile means for circulating one medium in an elongated fluent and refluent path, and flow-pipe means for circulating the other medium co-extensively with said first named medium and for positively directing said other medium in fluentand refluent paths transverse with respect to said elongated fluent and refluent path, whereby prolonged heat-transfer action is maintained (to-extensively with said elongated path; substantially as specified.

16. A heat-exchanging apparatus for hot and cold mediums. comprising. flow-pipe means for circulating one medium in multiple elongated fluent and refiuent paths, and with said elongated multiple paths; substanbaifle means for circulating the other metially as specified. 10 dium co-extensively with said first named Signed in, the presence of two subscribing medium and for positively directing said witnesses.

other medium in fluent and refluent paths JOHN I. THOMPSON. transverse with respect to said elongated \Vitnesses: multiple paths, whereby prolonged heat- NORMAN H. WARDALE,

transfer action is maintained co-extensively R. D. PLATT. 

